I've never thought about it before. They aren't the prettiest of surface mounted accessories. I hate the back boxes on these as they usually have many mounting hole positions which may need sealing in an environment open to moisture which may run down walls.
Also, I take it that it'll be conduit cable management for which they're suited and not square-line mini-trunking with dollops of white silicone filling gaps around square pegs in round holes.
Cant see that it makes a lot of difference to being a flush mounted socket in a kitchen, would advise the sockets are RCD protected for obvious reasons and I guess a squirt of silicon between the backbox and wall.
You see sockets like this in many a kitchen so I dont really see a problem, Obviously keep away from water but kitchens do need power.
Its not a problem as far as regs go. I have done it many times with no issues. Used 2.5 T+E into steel conduit into metal clad surface box. Job done. They are no more dangerous than any other socket.
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